Control circuit for an A.C. discharge lamp

Abstract

A control circuit comprising a series transductor coupled between an A.C. source and an A.C. discharge lamp. The control windings of the series transductor are connected to the A.C. source through a filter, a full-wave rectifier, and a substantially capacitive impedance. As a result the total reactive effect is reduced.

I claim: 
     
       1. A control circuit for an A.C. discharge lamp (4) comprising a series transductor having control windings (S1, S2) coupled between the A.C. source and the lamp (4), the control windings (S1, S2) of the series transductor being connected to the A.C. source through a filter (2) and a full-wave rectifier (1), and a substantially capacitive variable impedance (5) in the control winding circuit. 
     
     
       2. A control circuit as in claim 1 in which the capacitive variable impedance (5) is a variable transformer (6) in parallel connection with a capacitor (7). 
     
     
       3. A control circuit as claimed in claim 2, characterized by the variable device being a variable transformer (6) in connection with a capacitor (7).